Dear R help-list reader, I have a grouping variable C<-c(1,2,3) which gives me the plot symbols in a xyplot (lattice library) in three different colors, according the group variable. xyplot(A ~ B), group=factor(C)) if I now apply the panel.xyplot / panel.loess all the colors are changing back to red. xyplot(A ~ B), group=factor(C)), panel = function(x, y) { panel.grid(h=-1, v= 2) panel.xyplot(x, y) panel.loess(x,y, span=1) }, aspect = "xy") I'm wondering if anyone knows a easy way how I could retain the colors of the plot symbols according to the grouping variable. Yours Frank -- Frank Mattes, MD e-mail: f.mattes at ucl.ac.uk Department of Virology fax 0044(0)207 8302854 Royal Free Hospital and tel 0044(0)207 8302997 University College Medical School London